Rotating union for compressed air and more – DEUBLIN 1005 series

The rotating union from this series has been an integral component of the DEUBLIN programme for decades, and like all other rotating unions, it has been continuously developed.

This rotating union is used in the field of dynamic tire pressure control during operation for commercial vehicles.

Mobile agricultural machines, such as tractors or combine harvesters, as well as construction vehicles, drive across a range of solid surfaces compacted to varying degrees and surfaces of varying levels of sensitivity. Examples include pastures, arable land, forest floor, sand, clay soil, gravel and asphalt.

Since the machines are becoming larger and heavier, it is no longer adequate, and definitely not energy-efficient, to maintain ‘one air pressure for all tasks’. Protecting the soil on-site, safety and tire service life on the road are almost diametrically opposed.

Lower tire pressure in the field increases the tire contact area, which results in a reduced track depth and thereby the diesel-draining bulldozer effect. This way, soil compaction is avoided, helping to achieve a more uniform crop, better harvests, and optimised cultivation for the subsequent crop. Moreover, rain water can seep away quicker, which prevents soil erosion and flooding.

Meanwhile, higher tire pressure on road surfaces achieves a longer tire service life, lower roll resistance and greater safety when steering and braking – especially at higher speeds. This results in lower costs and reduced fuel consumption.

It is therefore recommended to adjust the air pressure in the tires to the requirements at hand, whereby trailer or attachments loads, the specific handling loads, as well as the expected slippage are now included in the parametrisation. The rule of thumb is: “As little air pressure as possible, as much air pressure as necessary.”

The pressure should be at 0.5 to 1.2 bar when driving in the field, and around 2 to 2.5 bar when driving on the road.

However, it would require immense effort to manually adjust the air pressure at each change of surface, especially with field cultivation and transport tasks alternating frequently. The dynamic tire pressure control system handles this task. It is available in various versions: for retrofitting or fully integrated ex vehicle manufacturer. The objective is to adapt the tire pressure from the driver’s seat at the touch of a button or via touchscreen function in continuous operation while rotating, optimising the vehicle.

While we prefer not to evaluate the advantages and disadvantages of a single- or dual-circuit system at this point, it is clear that an interface is required between the supply lines and the rotating tires for the compressed air supply. This can be realised e.g. by using a series 1005 rotating union by DEUBLIN . This rotating union accepts the compressed air from the compressor through the compressed air pipe on the stator side, and directs it into the rotating wheel via the rotor.

For retrofitting, an external attachment is often used, whereby the rotating union is superimposed on the front edge of the axle hub. Thanks to the compact design of this rotating union, in-axle constructions are equally possible, whereby the manifold is sunk into axle, and only the connection thread protrudes. Since the compression of the sealing elements in the rotating union is based on the balanced mechanical seal principle, the pneumatic force acts on the defined actuating and restoring forces, rather than the seal. This achieves a long service life through minimal wear.

However, a 1005 rotating union can do more than just bring compressed air to its destination. It is also used in the field of machining processes, where it ensures compressed air supply and/or hydraulics in machining centres, or even manage vacuums. Here, typical tasks include tightening and releasing work-pieces.

With technical base parameters of up to 10 bar of air pressure, up to 70 bar hydraulics and 7 kPa vacuums in compact and light design, this rotating union is a true multi-talent with a rotation speed ranging up to 3500 min^-1 as standard, and 10,000 min^-1 for special designs. In addition, various mechanical seal combinations, such as carbon graphite, tool steel, ceramics or silicon carbide ensure optimal operation, a long service-life and low maintenance.

Customised solutions for special tasks or other parameters can be developed with DEUBLIN’s manufacturer engineering – e.g. for higher temperatures, other pressure ranges or rotation speeds, with special materials for the rotor or other specifications.
This makes the 1005 series rotating union a relevant solution for a great range of tasks beyond compressed air.